1. Field of the Invention
This invention relates to a fibrous insulating material used for various furnaces and also to an insulating wall using such a fibrous insulating material.
2. Description of the Prior Art
The ceramic fiber blanket (or felt) used as insulating material is usually manufactured in a continuous long form, and it is thus cut to a suitable length and rolled for shipment as shown in FIG. 9. When applying it to a furnace inner surface or the like, in a stacked manner it is cut to a suitable length, and the cut ceramic fiber blanket pieces are applied to the furnace wall in the form of a stack by using securing means or bonded to the furnace wall. The above mentioned art of using the ceramic fiber blanket (or felt) has been disclosed in Japanese Patent Publications Nos. 39825/1971 and 14085/1978.
However, this blanket is very light and soft like cotton, so that it is likely to be broken or elongated at the time of installation unless it is handled very carefully, thus requiring considerable time for installation work. In addition, it has been the practice to secure it to the furnace wall by using bolts, nuts or rods made of heat-resistant alloy. Use of such mounting members for the installation not only requires time for installation work but requires the furnace outer wall to be sufficiently strong to support the weight of these mounting members.
When using such ceramic fiber blanket strip, therefore, it has been applied in a considerably long form for increasing the installation efficiency. However, the longer the blanket piece the greater is the thermal shrinkage so that a gap results between adjacent pieces in the extreme case, that is, the installation efficiency and performance of installation surface go counter to each other.